Add MailerSend and template-based email verification

Introduced support for MailerSend as an email provider alongside SMTP, with configuration options in settings. Added Jinja2-based multi-language email templates for verification emails, and refactored the email sending logic to use these templates and support language selection based on user country code. Updated related services and API endpoints to pass country code and handle new response formats. Added dependencies for Jinja2 and MailerSend.

app/router/auth.py

@@ -331,6 +331,7 @@ async def oauth_token(
                 user.email,
                 ip_address,
                 user_agent,
+                user.country_code,
             )
 
             # 记录需要二次验证的登录尝试

app/router/v2/session_verify.py

@@ -101,7 +101,14 @@ async def verify_session(
                 if settings.enable_email_verification:
                     await LoginSessionService.set_login_method(user_id, token_id, "mail", redis)
                     await EmailVerificationService.send_verification_email(
-                        db, redis, user_id, current_user.username, current_user.email, ip_address, user_agent
+                        db,
+                        redis,
+                        user_id,
+                        current_user.username,
+                        current_user.email,
+                        ip_address,
+                        user_agent,
+                        current_user.country_code,
                     )
                     verify_method = "mail"
                     raise VerifyFailedError("用户TOTP已被删除，已切换到邮件验证")
@@ -162,7 +169,14 @@ async def verify_session(
         if hasattr(e, "should_reissue") and e.should_reissue and verify_method == "mail":
             try:
                 await EmailVerificationService.send_verification_email(
-                    db, redis, user_id, current_user.username, current_user.email, ip_address, user_agent
+                    db,
+                    redis,
+                    user_id,
+                    current_user.username,
+                    current_user.email,
+                    ip_address,
+                    user_agent,
+                    current_user.country_code,
                 )
                 error_response["reissued"] = True
             except Exception:
@@ -203,7 +217,7 @@ async def reissue_verification_code(
 
     try:
         user_id = current_user.id
-        success, message = await EmailVerificationService.resend_verification_code(
+        success, message, _ = await EmailVerificationService.resend_verification_code(
             db,
             redis,
             user_id,
@@ -211,6 +225,7 @@ async def reissue_verification_code(
             current_user.email,
             ip_address,
             user_agent,
+            current_user.country_code,
         )
 
         return SessionReissueResponse(success=success, message=message)
@@ -241,7 +256,7 @@ async def fallback_email(
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="当前会话不需要回退")
 
     await LoginSessionService.set_login_method(current_user.id, token_id, "mail", redis)
-    success, message = await EmailVerificationService.resend_verification_code(
+    success, message, _ = await EmailVerificationService.resend_verification_code(
         db,
         redis,
         current_user.id,
@@ -249,6 +264,7 @@ async def fallback_email(
         current_user.email,
         ip_address,
         user_agent,
+        current_user.country_code,
     )
     if not success:
         log("Verification").error(